The present invention relates to novel onium gallates or gallates of organometallic complexes which are cationic initiators of polymerization, and to the use of such novel gallates for the polymerization or crosslinking of functional polymers or monomers by photochemical activation, or activation under an electron beam.
Onium salts or salts of organometallic complexes are well known as initiators of the cationic polymerization of monomers or of polymers substituted by functional groups of the epoxy or vinyl ether type, and any other cationically polymerized media and the like (U.S. Pat. Nos. 4,069,094; 4,450,360; 4,576,999 and 4,640,967; Canadian Patent No. 1,274,646; European Application EP-A-203,829). It has been observed that the best results are obtained when the anion of the initiator salt is SbF.sub.6.sup.- ; or tetrakispentafluorophenyl borate, (C.sub.6 F.sub.5).sub.4 B.sup.-.